Removing Pulley

[Galwaylotus]

I need to remove the crank pulley from my twin cam. Is it feasible to do this in situ? Do I need to drain the engine oil first? Does the radiator need to come out? I'm planning to have a double pulley made so that I can run the alternator on a separate belt from the water pump. I plan to space the fan pulley forward and run the pump from the new crankshaft front pulley groove. I don't have a garage and need to do this in the drive so I want to know how much is work involved. I know I'll probably need lonnger fan pulley attaching screws. Does anyone know the thread size?

Any information is most welcome. Thanks all!

[paddy]

Don't you risk putting more strain on the pump bearing by using the front belt for that? Why not use front belt for the alternator?

Paddy

[Galwaylotus]

My thought was that there needs to be very little tension on the pump belt but the alternator may need significantly more. I'll need to space the fan out to clear the double crank pulley so it seems easier to get a spacer made that will go behind the pump pulley and move it and the fan out together. If there's more tension on the pump pulley required than I thought, I can easily go the other route.

Still waiting on an answer to my questions though.

[types26/36]

Is it feasible to do this in situ?
Do I need to drain the engine oil first?
Does the radiator need to come out?
Does anyone know the thread size?

Yes, you should be able to do it in situ although you may have to loose the eng mounts to raise the front slightly.
No need to drain oil.
Yes, you will need the rad out.
The four bolts are usually 1/4 unc but I have seen the pully hub with 6mm bolts.

[garyeanderson]

Crank pulley bolt is a 7/16 unf, water pump pulley bolts are 1/4 unc.

You may need to disconnect a motor mount (maybe both) I have not done this before. I remember about a 1/2 inch in front of the pan before the front crossmember. Anyway I took these 2 pictures, the critical dimensions are 2 7/8 inch and 1 9/16 inch (there is 3/8 inch that needs to be added do to the rule), to clear the end of the crank snout it has to slide forward 1 5/16 inch to get it off. Add another 1/2 inch or so for the double sheave pulley.

p-a

4 inch crank pulley, 7/16 unf crank bolt, and special thick 100E 6379 washer. The recess is the reason for the thick washer so it will hold the torque without deforming.

[Galwaylotus]

Thanks, lads. Ye always come through when needed!!

[AHM]

How will you get the correct tension on the water pump?

[elan_fan]

How will you get the correct tension on the water pump?

By using a Europa twincam belt